220.127.116.11.1.2.4 Device type
The device type is specified by the
rule portion of the plain text query value. The value, represented by the
device-type ABNF rule, is any string that specifies a
device type. "SP" specifies a SmartPhone and "PPC"
specifies a PocketPC. Other client devices send unique strings for their
specific device type. Each request from a client device MUST include the same
device type string.